A packed house of more than 100 people attended a screening of a new documentary, “Dorothea’s Tears,” about the impact of the closing of hundreds of state mental hospitals during the “deinstitutionalization” movement of the 1960s and ’70s.

So many people showed up for the Bethel Cinema event that the film was moved from one of the smaller screens in the multiplex to the largest auditorium.

The film focuses on the Fairfield Hills state hospital in Newtown which operated from the 1930s through the 1990s. “Dorothea’s Tears” also examines the terrible irony of the same town later becoming the scene of the Sandy Hook Elementary School massacre, perpetrated by a mentally ill young man.

Two of the filmmakers spoke at the screening, Keith Maciog (who co-wrote and co-directed with Geer Teng) and executive producer Richard Falco.

The film’s title is derived from the 19th-century social reformer Dorothea Dix, whose reporting on the mistreatment of the mentally ill in prisons and privately run facilities led to a movement to build state hospitals all across the country.

In the 1960s, a move to integrate the mentally ill into society led to hospital closings around the country. The nation went from a peak of 558,239 beds in state hospitals in 1955 to fewer than 40,000 beds in 2016 (in the meantime, the population more than doubled).

While some of the nation’s mental hospitals were criticized for their care and facilities, Fairfield Hills was considered a humane facility where, for instance, every patient’s room had a window. “We were safe and they were safe,” an employee says in the film.

“It was one of the largest social experiments in history,” a mental expert says of the closing of so many state hospitals, adding, “The problem is we didn’t create anything to replace it.”

Many severely mentally ill people with no family members are left to fend for themselves as homeless people or are imprisoned for their anti-social public behavior. (The film includes a graphic surveillance video of police tasering a clearly mentally unbalanced homeless man).

“It’s a very important issue for us and one, unfortunately, we see as ongoing,” Falco said after the movie. “We are trying to bring the issue to the public.”

Falco and Maciog both said they are not implying that the Sandy Hook shooting was the result of state hospital closings, but that the steady cuts of funding for mental health programs has run parallel to the startling rise in mass killings.

Putting deinstitutionalization in place was part of a national change in the treatment of the mentally ill. “The hospitals were overpopulated and medications were changing (in ways that led) doctors to think that they could treat people out in the community,” Falco said.

One member of the audience pointed out that it is hard to be sure that the mentally ill are getting the proper medication when they are not in a facility. The woman’s daughter often refused to take her medication, complaining that she couldn’t stand the side effects.

“Her rights superseded the ability of the (outpatient) program to treat her,” she said.

The mental health-care crisis is a problem without any simple solutions, Falco said, but he hopes the film might cause people to see what they might do on their own level to alleviate the problem.

“Our hope is that the film can be a catalyst — plant a seed. I hope people will go back to their communities and see how they can address some of these issues,” he said.